Gesture detection provides a convenient way to control operation of a mobile device like a Smartphone by means of a finger or pen. For example, it allows users to simply interact with software and hardware without the need of a separate keyboard. Commonly touch screens are used and the position and specific movement of a finger or pen touching the screen is recorded by the system and translated into certain actions, like flipping a page of a virtual book or starting and interacting with an application. In such cases, however, the screen has to be touched and usually needs to be turned on to be interfaced.